Search for neutrinos from decaying dark matter with IceCube: IceCube Collaboration

Area of Science:

• Astrophysics
• Particle Physics
• Cosmology

Background:

• The IceCube Neutrino Observatory has detected high-energy astrophysical neutrinos.
• This observation has spurred interest in theoretical models involving PeV-mass decaying dark matter particles as a potential source.
• Understanding the nature of dark matter is a fundamental challenge in modern physics.

Purpose of the Study:

• To experimentally test the hypothesis that high-energy astrophysical neutrinos originate from decaying dark matter particles.
• To derive constraints on the properties of dark matter, specifically its lifetime, based on neutrino flux observations.

Main Methods:

• Two dedicated analyses of IceCube data were performed.
• One analysis utilized 6 years of muon neutrino 'track' events from the Northern Hemisphere.
• The second analysis employed 2 years of 'cascade' events covering the full sky.

Main Results:

• Both analyses fitted known background components and the hypothetical neutrino flux from unstable dark matter to the experimental data.
• No significant excess of neutrinos attributable to decaying dark matter was observed in either analysis.
• The study derived lower limits on the lifetime of dark matter particles.

Conclusions:

• The strongest constraints to date were placed on the lifetime of PeV-mass dark matter particles.
• Lifetimes shorter than a specific value were excluded at 90% confidence level for dark matter masses above a certain threshold.
• The results disfavor simple models of decaying dark matter as the primary source of observed high-energy astrophysical neutrinos.